import  turtle

len = 150
angle = 90

turtle.shape("turtle")
turtle.pensize(5)
turtle.color("red", "green")

shapeID = input("请输入绘制图形代码：4（正方形），其他提示输入错误：")

if shapeID == "4":
	turtle.forward(len)
	turtle.right(angle)
	turtle.forward(len)
	turtle.right(angle)
	turtle.forward(len)
	turtle.right(angle)
	turtle.forward(len)
	turtle.right(angle)
else:
	print("绘制图形代码选择错误。")
	turtle.write("绘制图形代码选择错误。")